Henry Calvert Simons was an American economist at the University of Chicago. His anti-trust and monetarist models influenced the Chicago school of economics. Simons is noted for a definition of economic income, developed in common with Robert M. Haig, known as the Haig-Simons equation; this definition of income has strongly influenced the modern American tax structure. In one of his better known essays, A Positive Program for Laissez Faire (1934) Simons set out a program of reform to bring private enterprise back to life during the Great Depression. "Eliminate all forms of monopolistic market power, to include the breakup of large oligopolistic corporations and application of anti- trust laws to labor unions. A Federal incorporation law could be used to limit corporation size and where technology required giant firms for reasons of low cost production the Federal government should own and operate them